Figure 3. Effect of PEG-FGF2 conjugates on promoting proliferation and migration of HUVECs. (A ) Percent cell viability of HUVECs after treatment with various concentrations of PEG-FGF2 conjugates, FGF2, and PBS (control), as determined by CCK-8 assay. (B ) Representative images of immunofluorescence staining of Ki67 positive HUVECs (red). Nuclei were stained with DAPI (blue). Scale bar = 200 μm. (C ) Quantitative analysis of Ki67-positive HUVECs (n = 5). **P < 0.01,***P < 0.001 vs. control group;##P < 0.01 vs. FGF2 group. (D, E ) Scratch wound healing assay of HUVECs in the indicated groups for 24 h. The red dotted lines represent the wound boundary. Scale bar = 100 μm (n = 5). All data are displayed as means ± SEM.***P < 0.001 vs. control group;#P < 0.05 vs. FGF2 group; n.s., no significance.